I’m looking for a bit of guidance. I’m looking at installing level 2 ev charger. I have an existing circuit that has a 40 amp break with awg 6-3 wire, a hot tub that is no longer in use. The run was a bit longer so that’s why I think they used awg 6 instead of awg 8. The charger I want to install can be hardwired and calls for awg 8. Can I put a junction box right below the charger and splice the wires going from awg 6 to awg 8 for the final 2 feet to the charger. One reason I’d like to do it this way is because the wire will be coming straight down from the attic straight down turn 180 degrees to come straight vertical into the charger. The NMD 90 6-3 wire is quite stiff and I was worried about putting to tight of a bend into it. The charger only uses the two hots and a ground, so also hook up the two hots, hook the ground, cut flush the neutral and wire nut it? In my province BC, Canada, we can apply for homeowner permits, which I’m going to get and this will inspected, I just don’t want to waste mine and the inspectors time, so just trying to do it right the first time. Thanks for the advice.
Comments
Loon610 OP t1_ir2kund wrote
That sounds like Reddit.
slugo17 t1_ir338yy wrote
That's a pro move that predates Reddit. Same rule applied back when forums ruled the internet.
rivalarrival t1_ir3a6x1 wrote
Yeah, this is known as Godwin's Law.
somecasper t1_ir3msrw wrote
Unless I'm having a serious Berenstain moment, Godwin's Law is that any argument, if it goes on long enough, will eventually escalate to accusations of Nazism.
Edit: Goddamn you, I see what you did there.
TrumpsPissSoakedWig t1_ir5k2jh wrote
Escalated to final solution quickly.
snellface t1_ir4jut5 wrote
Special educational operation?
nill0c t1_ir3amxk wrote
Yeah, and I think he came up with it for BBS posts.
newredditsucks t1_ir3srk8 wrote
Well played. I did not see that coming.
[deleted] t1_ir3b4no wrote
[removed]
[deleted] t1_ir4yfyb wrote
[removed]
sofa_king_ugly t1_ir4tvm2 wrote
Whenever my mom wanted something done around the house she'd start doing it herself. Dad was usually out building fences or evicting raccoons or whatever but she knew I wouldn't be able to stand not doing it. I found out later that she wasn't even really trying. My wife still uses the same tactic on me.
gottapoop t1_ir3od00 wrote
Electrician here. Have you checked if the existing wire is aluminum or copper?
It's quite common to run #6 aluminum instead of #8 copper for 40 or 50a circuits because of the cost savings.
If it is aluminum you'll need to use proper connectors to junction to copper but really if possible it's most likely the simplest to just run the 6/3 straight to the charger.
Loon610 OP t1_ir3pqir wrote
It is copper, thanks for the heads up though.
St0nkHodler t1_ir54tuv wrote
This is how my electrician did our EV charger. Pulled the 6/3 Alum from the old hot tub connection and ran it to the EV charger with copper junctions. Ours is on a 60A breaker and we get 48A to the Tesla.
Expensive_View4349 t1_ir4qi60 wrote
Why so huge cable, just go down to Walmart and by a TCP cable and u get 8 parts!!! The manufacturer have no idea what they talk about. Buy a cat 6A imagining charging at 100 gigabits per second!!!
Westerdutch t1_ir2wtad wrote
The reddit version of Cunninghams Law.
ichliebekohlmeisen t1_ir37mmu wrote
That phenomena is called Winstead’s Law. People can’t help but correct wrong information.
rivalarrival t1_ir3ace9 wrote
Pretty sure it's the Pareto Principle.
r2rknot t1_ir58cif wrote
That is the 80-20 thing.
rivalarrival t1_ir5e48e wrote
I thought the 80/20 thing was Hanlon's Razor.
r2rknot t1_ir5e9nv wrote
Ok, you caught me the first time, but I'm on to you mister!
rivalarrival t1_ir5efm1 wrote
Oh, I'm thinking of Rule 34.
Jinked t1_ir61fxl wrote
Man, id love to think i learned a few things in this comment chain..but now i feel like im just aware of a couple new terms and ima have to look em up to get them straightened out
rivalarrival t1_ir62h1p wrote
Lol, ok, add "Cunningham's Law" to your list. It is, actually, the relevant concept.
gjr23 t1_ir390ge wrote
Wrong.
You also missed the part about grammar and punctuation. You missed the “an” before incorrect.
SteelToeSnow t1_ir1j1w8 wrote
Don't downsize if you don't have to. Every splice is a place where it can fail, whenever possible just run whole lengths.
Don't cut the third wire, just cap it off and tuck it into the back of the box. As an electrician, I fucking hate seeing wires chopped close to the box. In ten years or whatever, maybe codes have changed and you'll need a neutral, but now there's not enough to work with and it becomes a major pain in the ass.
mname t1_ir32962 wrote
This guy gets it. Knows a future PITA when he sees one!!!
TheRealRacketear t1_ir478gc wrote
Why would code require a neutral? A neutral on a 240v circuit provides nothing in terms of safety.
I agree with cuttin and capping, but this isn't a good reason to do it.
FavoritesBot t1_ir4bqcb wrote
But it lets you run 120v devices
frollard t1_ir4gpqu wrote
Some newfangled device might want it, not that code will change. (like a stove with 120v plugs, or merely breaking it out to another sub panel)
SteelToeSnow t1_ir5yqig wrote
Things change. Used to be you didn't need a neutral in a light switch. Now you do.
Used to be you didn't need a neutral in a dryer plug. Now you do.
Used to be you didn't need bond wire in emt. Now you do.
Code changes. Constantly.
The point is that cutting wires flush to the box doesn't help anything, it just means now there's a hindrance in the future. Maybe code changes in the future. Maybe a future person living in the house wants to do something else with that wire, but now they can't, bc an important wire is snipped.
WackyWRZ t1_ir4xmi6 wrote
3-wire dryers used to be OK and now they have to be 4-wire with a neutral.
TheRealRacketear t1_ir58lf1 wrote
They are still ok though. If that's what is wired.
1971CB350 t1_ir1h7ug wrote
Ask your inspector/permit office. I’ve always found those folks to be very helpful. It’s your tax dollars, use them when you need them!
Loon610 OP t1_ir1ic1h wrote
Thanks for the input.
1971CB350 t1_ir2hhy7 wrote
I wish I could give you a specific answer, but codes vary by region and you’ll want to meet the expectations of the person doing the final inspection.
Loon610 OP t1_ir2kso6 wrote
Thanks again, I’ve dealt with other inspectors when doing renovations, and some are clueless, the one I’m thinking of is the district inspector when I did my wood stove. When contacting offices that do inspections I have found usually people answering phones are very inexperienced, and the people with the knowledge are out on the road working. Usually when I have met the inspectors that are actually the qualified ones they’re pretty good source of information. It’s just hard talking to these people until they show up to do the inspection. I will have 3 inspections available with my permit until they start to charge me for additional inspections, but I would like to be one and done. I also find these types of projects a great way to learn more, I’ve caught multiple errors in my house from learning from these projects, and as shitty and snarky Reddit can be sometimes there are some very helpful resourceful people, so that’s why I like asking here, that gives me jump off point to read more and then be able to ask more questions when the inspector shows up haha.
Eljefedelmundo t1_ir2xmis wrote
my advice is to go down to the office with pictures and drawings of what you want to do early, like 8-8:30AM, before the field inspectors leave. Maybe bring some donuts or coffee cake too, show them what you want to do, and ask how they would do it, if they were doing it themselves. You probably get 2 or more arguing over how to do it, but it's all good advice.
jackdawson1049 t1_ir54fdu wrote
Ask for a pre construction meeting with the inspector. Now you can ask him your questions.
Viper67857 t1_ir1ud5a wrote
Instead of a junction box, I would put in a disconnect...
how_could_this_be t1_ir1x0ms wrote
Agree. A lot of high draw circuit can be benefit from having a disconnect near the draw. This is like a perfect place for a disconnect to happen.
Or maybe a small surface mounted sub panel? That would eliminate any concern for downsizing wire gauge, also allows for proper and safe way to add circuits should you need it near that location.
nocturnal311 t1_ir2maqo wrote
What would a disconnect have to do with the draw? Sub panel seems a little expensive and unnecessary
how_could_this_be t1_ir2o9jq wrote
It's true throwing suggestion out is free.. it totally depends on OP's situation and plan.
I am suggesting based on how I would plan it. Disconnect can be handy when you found the plug damage / arcing but breaker did not trip. Think drive out with the cable plugged in.
Or if OP ever decided to use his EV as backup battery for the house, then a shutoff can become something that is more necessary..
The sub panel is also situational.. a small subpanel can be not too pricy - small ones can be have for between $30~50. If there is possibilities of expansion this can totally be a choice
Doctor_Frasier_Crane t1_ir2t7yy wrote
Please tell me where I can get sub panels at that price. Anything in Canada is at least $150.
how_could_this_be t1_ir2x5vc wrote
This is one example. I know homeline is annoying but at this price.. I won't complain
I don't know if your local code allows this though.. no idea about Canada's rule
Doctor_Frasier_Crane t1_ir2zm9y wrote
Ok, not that bad. Only 4x the price at $104 in Canuck bucks! I was off on my guesstimating. :)
how_could_this_be t1_ir30bmg wrote
Ouch.. sorry to hear that.
If you look at similar items on that page there is a long list of similar priced breaker boxes.
Just throwing a bit more lead, hopefully some of them can be sourced near you with more reasonable price…
Viper67857 t1_ir3310p wrote
>What would a disconnect have to do with the draw?
Would you bother with a big disconnect box for a 1A circuit running a small fan? Doubtful.. But I bet you have one going to your HVAC.
>Sub panel seems a little expensive and unnecessary
I agree.. This circuit isn't really big enough to split off additional loads unless the charger is taken out of the picture. Swapping the breaker feeding it from a 40A to a 50A and putting in a 50A subpanel would cost well over CA$100 and you could add what? A coffee maker? It's best not to run a circuit at capacity for long periods of time, especially over distance, and lv2 chargers take several hours to charge a dead EV. I wouldn't add anything to this circuit...
boxsterguy t1_ir3hylz wrote
You're overestimating what a level 2 charger needs. 30A is more than enough to overnight charge anything less than a Hummer EV. Adding more is unnecessary and a little silly, but I wouldn't say it's necessarily unsafe.
rsfrisch t1_ir3vqqa wrote
It depends, my gen3 Tesla charger requires a 60a 2p breaker and pulls 48a Max at 240v. You can set it lower... Either on the charger or the car. But there is still a big difference in charging times from 11kw to 5-6kw.
It's nice to have the flexibility to charge a little faster.
frollard t1_ir4h0bo wrote
Sanity check, can support 60a breaker, not requires. You can program it to use a 15 amp if necessary.
rsfrisch t1_ir58ber wrote
Your right, I misspoke
My point was that you should try to maximize your level 2 charger as much as possible. Charging a model y from like 20 to 90% shouldn't take more than 12hrs... And 8 hrs would be better. 30a at 240v will do that.
frollard t1_ir8f0g1 wrote
Go for the most that is possible and reasonable, agreed to a point. There are very very few times in my 4 years I have needed to get home from a highway trip empty to need to turn around and do it again the next day. Overkill electrical is a convenience for sure but the price goes up way higher, and many people like me are stuck with 100 amp service. Jamming a current gen max spec continuous duty 60 breaker has ramifications for the whole home load calculations if I ever want a/c, heat pump, etc. Just the cost of the wire alone is astonishing these days. Upping my panel to 200a service would have long term consequences on my property tax bill for a super rare highway trip + turn around and do it again occurrence.
Viper67857 t1_ir3k6br wrote
Transmission loss, AC/DC conversion, and keeping the battery temperature regulated draws more current than 30A to actually charge at 30A. Also, I didn't say it would be unsafe, because the breaker should trip if you're overloading the circuit, just that there isn't really room to bother adding anything.
Derragon t1_ir3rzdw wrote
Sub panel is against code in this case as it allows other loads to be added to the circuit. In Canada it must be dedicated.
Editing myself: forgot you could just... you know, use the sub panel to provide the feed (which is allowed). The above info is incorrect, you can do Main -> Sub -> Charger.
rsfrisch t1_ir3uvtk wrote
The plug from the charger is a means of disconnect.
Forget a jb if you don't need it, using a larger size wire isn't a problem as long as it fits the lugs.
Derragon t1_ir3rwst wrote
Yup. Disconnect is required by code for 240V chargers.
Itisd t1_ir1fep7 wrote
Are you sure the charger will not accept a #6 wire? If possible I would run the #6 straight into the charger. I would avoid any junction between a #6 and a #8 wire if possible. How long is the wire run front the panel to the proposed charger location?
Loon610 OP t1_ir1hhf9 wrote
I tried reaching out the company via email no response yet. It’s not far maybe 30’ only trying to use the 6 gauge because it’s already there from the previous owners hot tub.
hamsterdave t1_ir20p01 wrote
If it's a typical level 2 charger, ~50A for Leaf and Tesla and a few others, up to 80A (!) for the Bolt, I certainly hope it will accept 6 awg, 8awg is only rated for 40A in residential wiring.
What type of charger is it? The Tesla level 2 charger can accept cabling from above or below, it's got knockouts on both ends. It definitely accepts 6awg, I installed mine last winter.
EVEngineer t1_ir2kvld wrote
Huh?
Leaf has 30amp charger and the bolt has a 48 amp charger
hamsterdave t1_ir2muaz wrote
Chevy advertises up to 80A on their type 2 and the Leaf website doesn't seem to sell a Nissan branded Level 2 charger, but their website links directly to a 48A unit from Wallbox.
EVEngineer t1_ir2xfdt wrote
That is very confusing marketing from Chevy, but the bolt has a 48 amp onboard charger for AC charging. You can use any evse you want, but are wasting your money past 48amps.
On the leaf too, it's not about the wallbox (evse). You need to search for the 'onboard charger amperage' to figure out what the vehicle is capable of and then buy a evse that is rated for that or more. The leaf is rated for 6.6 kw or about 30amps on 240V.
TURBO2529 t1_ir39xxh wrote
Yeah, they are saying the wall charger maximum is 80A. Not that this year's car can handle it, which is a little misleading.
Itisd t1_ir1qpr9 wrote
The connectors on the charger, of somewhere in the documentation should indicate what wire sizes are acceptable. I would think that #6 should be acceptable, but obviously you need to confirm it with your particular unit.
Also, what is the amp draw of the unit?
Atomic-Decay t1_ir60yed wrote
Guaranteed a charge designed to handle #8 @40 amps will have lugs big enough to handle #6.
framerotblues t1_ir2hdnc wrote
OP, you're in Canada. Anyone in here talking about the NEC (the US national electrical code, NFPA 70) has an answer that cannot be validated in your country and even may differ in your local jurisdiction. You need to reference the Canadian Electrical Code, CSA-C22.1-21 and if you are unable to access it or need to purchase it, you need to contact an electrician.
I'm sure much of C22.1-21 is similar to the US NEC but there are particulars that are going to be different that may apply to your situation, especially as vehicle chargers are getting increased scrutiny.
Bhrunhilda t1_ir4drkl wrote
Most electrical distributors are open to the public. They all have a code book behind the counter. Just go and ask to look at it. They won’t mind.
benkeico t1_ir3krs0 wrote
Ok. I’m a apprentice electrician, and I’m doing a ev class right now. My info might be slightly off but I’m fairly confident.
As far as running 6’s then 8’s yes. It works. I wouldn’t use a junction box. I would use a disconnect. That’s code where I am.
Now. The big thing here is. Your car charger that you’re installing Is 40 amp, you can’t use a 40amp breaker. Your running continuous load. Your need 125% for overhead. So, If you have a 40amp charger you need a 50 amp breaker.
Loon610 OP t1_ir3pi4t wrote
Thanks for the help. The charger has adjustable dip switches so it can range from 16, 24,32,40 amp output, with the 40 amp breaker I was going to switch the dip switches to 32 as my current vehicle only takes 14 amps at 240v anyways. The reason for doing a larger rated charger now is my local area has rebates, I will be in the house for 30+ more years so presumably I will have an Ev at some point not just a PHEV, and the circuit is already there from a hot tub (previous owner)I have no desire to replace.
I got a hold of the manufacturer and they said the charger is capable of using 6 gauge. From other posters advice, here is my plan, either keep the 40amp breaker or possibly upgrade to 50amp, NMD 90 6-3 wire to a junction box in garage wall just on the other side of charger carport location, strip jacket (not insulation)of wire, then from the junction box run wire through flexible non metallic conduit straight into charger through the wall into carport where charger is. What’s your thoughts? Any ideas?
Wellcraft19 t1_ir4l1q7 wrote
You’re good and on the right track. I would just add that you’re not installing a ‘charger’ per se, but a fancy cable hanger.
The dip switches (good) are only there to communicate to the car (where the charger is located) how much current the car is allowed to draw. This so car [charger] does not draw more current than what the [house] infrastructure can support.
Level 2 ‘chargers’ are only a way to safely deliver 208/240 V AC to the car. People get overly hung on this [charger] and often spend far more than what they need. Or are a bit deceived of what the devices actually are and do.
But with a high static load (or high continuous load), it is imperative that all connections are properly done, are tight, as you will be pulling a decently high amperage for extended periods of time, and not like a clothes dryer (a comparable load) that often runs less than an hour, with load switching on and off during the time. A poor connection can easily overheat, leading to further heating. Etc.
Loon610 OP t1_ir5lswp wrote
Yeah I was reading more about EVSE vs charger yesterday. I didn’t really think of the charger in the car and the “charger” I’m installing is just a power supply. The good thing about the connections are the should be very simple. The connections at the breaker/panel, then straight to the EVSE with no splices and the charger is designed to be hardwired with terminal blocks and a bus bar.
Wellcraft19 t1_ir76gqf wrote
Like I said, you're good!
benkeico t1_ir50edh wrote
Add a disconnect not a junction box. Almost same price but it’s way better. Run number 6 and upgrade your breaker to 50 amp later when you want to run the charger at 40amps. Liquid tight is good, try not to use 90s they suck to pull through.
Sparkykc124 t1_ir1r18e wrote
I’m an electrician and what you’re doing is perfectly fine, provided the wiring is in conduit from the junction box to the charger. Is the 6-3 already at the j-box location? Do you have to re-route it? Honestly, even better is to bring the romex into a j-box and split out the conductors long enough to make it to the charger, splices are weak points.
eerun165 t1_ir1vim9 wrote
Not all jurisdictions require conduit.
Sparkykc124 t1_ir1w9o3 wrote
Well, no jurisdictions allow single conductors to be run outside of conduit/boxes. OP didn’t mention what type of #8 conductors would be used, so I assumed.
jkoudys t1_ir350h4 wrote
> no jurisdictions allow single conductors to be run outside of conduit/boxes
Wish the handyman who did half of the place I bought knew that. Nothing worse to see than thin black wire hopping between jboxes.
Sparkykc124 t1_ir36c4h wrote
Don’t look. I live in a 1911 built house and most everything in the walls and attic is knob and tube. What isn’t, was mostly done by 1950s and 70s handymen.
crankshaft123 t1_ir4zcb6 wrote
My first house was built in the 1930s. The guy I bought it from was an electrician. He was also a fucking hack. He replaced "all" of the original K&T wiring with romex and upgraded the panel from a 60A fuse panel to a 200A breaker panel. He did all of this work poorly, and very little of it was done to code.
All 2nd floor lighting circuits were still K&T. There were running splices in the basement and the attic. The main wire from the pole to the meter was replaced when the new panel was installed, but the penetration in the side of the house was never sealed, which meant that water collected in the bottom of the panel whenever it rained.
Over the course of 10 years, I spent countless hours discovering and repairing the previous owner's hack work.
Sparkykc124 t1_ir79ha7 wrote
Yeah, I can’t do things half ass, so sometimes it’s better if I just don’t do it. I actually have started rewiring but I will have to leave the first floor overhead lighting, which isn’t much, as it’s not worth putting holes in the plaster ceiling.
eerun165 t1_ir1xds0 wrote
True on the single conductor. The splice would also need to be in a box. Cable of appropriate type wouldn’t necessitate conduit.
Loon610 OP t1_ir2o3pi wrote
Thanks for the input. I have to reroute the 6-3. It’s about twice as much wire as I need. I managed to get a hold of the charger manufacturer and they said 6 gauge is okay. I was going to run the non metallic water tight flexible conduit from the vinyl siding to the charger about 2 feet. So no one would frown upon stripping the jacket on the NMD 90 at the start of the conduit and running it like that which would be more flexible. How tight of a bend radius could I put into NMD 90 6-3, I measured it slightly under 3/4 inch diameter, I read I could 5x the diameter as a radius. So I could put a 3.75” radius bend into wire? I know bending too tight can cause resistance to increase.
Sparkykc124 t1_ir32s5p wrote
> So no one would frown upon stripping the jacket on the NMD 90 at the start of the conduit and running it like that which would be more flexible
By code, the sheathed cable should enter a box with a connector before being stripped back. Though I’ve seen it done plenty like you’re saying. The other thing to consider is that NM is not listed for use in wet environments and sunlight will degrade the outer sheathing. You want to limit the amount of it that’s exposed to the elements. If it were me, I’d poke the romex through the sill plate, directly into the back of a 6x6 pvc box mounted to the siding, strip it back, roll and tape up the white, and come out of the box with non-metallic liquid tite into the charger. One thing to keep in mind is that it’s almost impossible to keep water out when you put a hole in the top of a box. If you can, come out the side of the box with your liquid tite, or even better, the bottom. Also, drill a couple small holes in the bottom, so when water does get into the box, it can drain out.
> I know bending too tight can cause resistance to increase
The electricity won’t care. Too tight of a bend puts strain on the jacketing and insulation. I don’t think you need to worry about that though, you have to try pretty hard to overbend wire.
Loon610 OP t1_ir3r8sl wrote
Thanks a lot for the info this has been very helpful. Just want to run one last thing by you. To clear two things up, the run from the panel to the charger will be up on wall of a garage, through the attic, down the other wall, so I will be going through the top plate not the sill plate. Also the junction box would be inside the garage, I plan on knocking out some drywall and having the junction box exposed to the inside of the garage, then running the conduit from there, so the only thing that should be exposed to the elements is the flexible conduit, the hole it passes though, and the charger what is suppose to be water proof when mounted in the correct orientation. So two questions, no problem going through the attic and down the walls right? Also the NMD being in the attic and on the interior of the garage wall would count as dry interior application, not a wet one right.
The company said 6 gauge is okay to run, and thanks to your advice I think, I will use this as my plan. Either keep the 40amp breaker or possibly upgrade to 50amp, NMD 90 6-3 wire to a junction box in garage wall just on the other side of charger carport location, strip jacket (not insulation)of wire, then from the junction box run wire through flexible non metallic conduit straight into charger through the wall into carport where charger is. What’s your thoughts? Thanks again for the help, you’ve been very informative.
Sparkykc124 t1_ir41s84 wrote
Yes, sounds like a good installation. Also, wouldn’t bother changing the breaker.
TiboQc t1_ir3xci6 wrote
Not the original commenter nor an electrician, but I did plenty of reading of the requirements here in Quebec before installing my Tesla charger with my electrician father-in-law. From my understanding: attic and wall absolutely count as dry environments, NMD is ok for those. Not sure why you need a junction box before going outside though.
About stripping the neutral wire before going into a conduit, I found this: "installing stripped Romex where the wire may be susceptible to damage is prohibited. This may include installation near sewage lines, bins, garage doors, and even those attached to the face of concrete walls!". Looks like it's ok to strip before going into a conduit, as long as the conduit protects well from environment, from external physical damage (animals, shovels) and is well waterproof (directly connecting to the charger or in a waterproof box).
You could also try to find a 6-2 wire, even better a NMWU so to avoid using a conduit and staying flexible, but those are pretty hard to find.
About the 40amp breaker, I know my Tesla model 3 can only take 32Amp so I kept my 8-3 with 40Amp breaker. Model Ys and some other cars can go a bit higher, but the charger can be configured to stay below 40Amps. If your charger doesn't go beyond 40 or you car use 32amp for example, no need to upgrade the breaker, but it's nice to have it easily upgradable when faster charging becomes available (e.g. your next car).
Anyways, just wanted to participate in the conversation, better have confirmation by a pro. Congrats on your EV, they are so much fun!
JerryfromCan t1_ir449st wrote
I have 6 gauge running into my chargers home/cottage Ontario. Wanted the additional in case we ever get to 80 amp (which requires a shut off right next in Ontario) which the Ford Lightning was supposed to be. Turning 6 gauge is not easy but I have learned that you can pretty much turn teck 3 4 wire 3 gauge on a dime if you work it hard enough in conduit so I will never complain about 6 gauge indoor wire again.
Derragon t1_ir3ruzu wrote
BC electrician here.
If it's 6/3 It's most likely aluminum but if it's copper that's awesome (just not as common as the aluminum is way cheaper). I do not recommend downsizing the wire for the last two feet, get the same gauge if you need to extend it (or don't extend it at all - EVs have very high extended loads and splices aren't great for that).
You will need to validate the breaker is GFI equipped (rule 86-306). You will also need to install a disconnect for a 240V charger (rule 86-304) that is within sight of the charger - this would be the place to make a junction.
As a reminder an EV charging circuit cannot be used for anything else apart from ventilation (rule 86-300), which will be necessary per rule 26-506.
Loon610 OP t1_ir3ut8e wrote
Thanks this is great info since you’re from BC. It is copper wire.
Couple questions. I’d like to keep as much in the garage as possible to keep the outside looking tidy, the setup is basically a garage next to a carport, same size and direction just a wall between them, on the opposite wall where the charger will go in the garage is the main service panel.
If the charger has a GFCI and is hardwired, I still need to wire in another GFCI, I know this is the case with the use of a plug and receptacle because who knows what someone will plug in, but I thought I could avoid this by hardwiring to ensure non gfci equipment are not used.
If I did wire the charger so it is mounted in the garage where the service panel is would the breaker on the panel count as disconnect within sight? I thought about this option to keep it out of sight/tidy and prevent theft. But with this case would any codes be violated if I passed the charger to vehicle cable through the wall dividing the garage and carport, so the only thing on the exterior is the vehicle charging lead with the controller on the inside of the garage.
Thanks again for the help, thanks for citing the rules, it’s very helpful, much appreciated.
Derragon t1_ir3xmc7 wrote
There still needs to be GFCI separate from the charger itself to cut power in case it fails (interrupter installed at supply)
I don't believe the breaker on the panel counts as a disconnect but I'm not sure on that. However it must be able to be locked open (which a standard breaker cannot be) per rule 86-304.2c which pretty much requires a separate disconnect regardless with a residential panel as they'll use a removable cartridge.
I am not sure you are allowed to do the passthrough of the charger through the wall either but you'd have to ask an inspector on that one.
Loon610 OP t1_ir3zj1a wrote
Thanks a lot again, I’ve been diving into the codes now. I found this article which is a good source but seems older. https://vancouver.ca/files/cov/EV-deplioyment-guidelines.pdf Looks like I’ve got lots of reading to do haha. I’ve got to apply for the permit through Technical Safety BC, any experience with them, just wondering how responsive and helpful they would be to emails and questions.
Derragon t1_ir42joj wrote
Honestly if you've never done any of this before I'd get an electrician to do it. EV chargers are straight up fire hazards if not done properly - not to discourage you from DIY stuff but an inspector isn't going to check every connection.
Loon610 OP t1_ir44gll wrote
Okay, thanks for the advice.
eerun165 t1_ir1ux78 wrote
This is typically acceptable as a means to account for voltage drop. Check to see if the charger accepts the larger size (many do). Then you can double check with the inspector so they’re aware of the charger does not accept the larger size. Your #8, per NEC, are properly covered by the 40A breaker.
Loon610 OP t1_ir1h6ul wrote
I understand this concern, but there will be no “outlet”, it will run about 30’ from the main panel, to the junction box, and about 1-2 feet from there to the hardwired charger. I’m avoiding a receptacle because then my kids can’t mess with unplug or plug charger in, harder to steal and no need for a new 280 dollar gfci breaker which is need if it’s no hardwired, the charger has a gfci built in, but I understand if it’s receptacle who knows what will be plugged in.
Dowie911 t1_ir3omtm wrote
Totally acceptable to do that.
Instead of cutting neutral wire, I would use it as a second ground. Tape it or use a marker to make it green, and it's even safer than before.
Only advice would be to splice it properly. Not sure if there's any 6 gauge marettes (wire nuts for Americans), but read the box and it will say if it's good for 6 and 8. If not, get one of those nut and u-bolt style ones, then wrap with the expensive 105° tape. Use an anti-oxidant such as noalux as well if its aluminum, just for code. If you want the noalux to work, make sure you rub it in with a wire brush, although this is unnecessary overkill in my opinion.
Edit: to clarify, this advice is all up to code in BC, Canada.
Exciting_Ad9005 t1_ir3q7ez wrote
Hey, I did this same thing not long ago for my Chevrolet volt plug. Use the larger wire only, don't splice it down into the smaller wire the last 2 feet. The wire is thick but it will still bend enough for you to go around corners. Less connections is better. Mine works like a charm, car charges waaaay faster now. I had left over stove wiring, so its oversized truly, but bigger is okay.
robnox t1_ir3z3kf wrote
I would read the electrical code in your region and just follow everything exactly. I did that for my install (but i’m in the US so I used the NEC).
Also do not use awg8, even if it is just a short distance. This could be an extreme fire hazard.
In my case I ended up using awg4 for the whole run to be more power efficient.
Good luck!
tired_and_fed_up t1_ir40jqq wrote
>Can I put a junction box right below the charger and splice the wires going from awg 6 to awg 8 for the final 2 feet to the charger.
Yes, but don't wire nut that. What you want is a tap connector.
https://www.homedepot.com/p/Polaris-4-14-AWG-Bagged-Insulated-Tap-Connector-Black-IT-4B/303577920
That will guarantee the connection is tight and won't come lose or arc.
[deleted] t1_ir1h8rh wrote
[deleted]
limitless__ t1_ir1hfjx wrote
Are you sure about this 8 gauge requirement? I have a Grizzl-E EVSE and it can handle 6 gauge just fine since it can deal with a 50 amp circuit and power at 40 amps.
Loon610 OP t1_ir1i3vo wrote
Thanks, for the info. That’s the charger I’m looking at, I noticed the owners manual called for 8 gauge, and my understanding has always been unless it stats otherwise that’s what you have to use. I emailed them asking about the 6 gauge, but haven’t got a response. Did you ask them or just wire it up and figure it out that way?
nocturnal311 t1_ir2nuge wrote
If it fits under the terminal it should be fine
aimfulwandering t1_ir3gmum wrote
I mean, no not really? The manual indeed does call for 8awg max, and also calls for crimp connectors: https://grizzl-e.com/wp-content/uploads/2022/09/Grizzl-E_Generation2Firmware_Manual_V1.8.pdf
That’s a pretty horrible terminal block design IMO, but it is what is it is.
I’d recommend bringing your 6WG to a disconnect, and then wiring #8 thhn or thwn in the short piece of conduit from the disconnect to the EVSE. Or, alternatively, just install a NEMA 14-50 outlet on the #6 and plug it in.
Check your local code though: a disconnect may be required anyways.
intashu t1_ir1jdsb wrote
Looking at your comments, for your specific use, you'd be just fine if it's wired in directly to the junction box properly.
I'd still check and see if your charger can fit 6awg wire just so it's consistant, but at 40ft to the breaker it shouldn't be an issue.
However, that being said.... Burning your house down because of what a stranger said on reddit isn't a good idea. I'd follow up with what the other comment said on getting some involvement from professionals before moving forward with the install.
buildyourown t1_ir1lpf2 wrote
Voltage drop is a concern with EV Chargers so you want the heavier gauge wire.
Smackysan t1_ir2b058 wrote
Westerdutch t1_ir2xb4f wrote
Huh, thats an interesting little doodad. So does everyone have the exact same meter in the US?
N5tp4nts t1_ir36424 wrote
I'm pretty sure the sockets are all the same pattern. Lots of different meter types but same socket.
Metsican t1_ir3b872 wrote
The ConnectDER is explicitly forbidden by multiple utility companies near me. This is after they did a pilot program with the product for solar installs.
Westerdutch t1_ir4fbev wrote
It does sound like it potentially allows for shady things to happen if you allow a device to exist between the meter and you installation (assuming these meters are used for billing purposes).
lvlint67 t1_ir2dags wrote
> Can I put a junction box right below the charger and splice the wires going from awg 6 to awg 8 for the final 2 feet to the charger
make sure the breaker meets your local codes with the wire downsize.. otherwise i'm not familiar with canada's electric codes.
Bumblee_Tuna t1_ir2kx6f wrote
We have a L2 with 48 amp, and it certainly accepts 6 awg,
Oldtimer_2 t1_ir2m2fx wrote
Call an expert.....
Filthymonster t1_ir2q88o wrote
I'd run the conduit right into the charger, don't bother downsizing the wire. The unused neutral should be left long enough for termination, and capped off and left inside the charger as well. The radius of the bend will be determined by the size of the conduit it's in but basically as long as you don't crunch it/put a kink in it it's a fine radius
awtivy t1_ir302jj wrote
Firstly in Canada we have tables in the CEC that dictate the maximum amperage for a certain gauge of wire. This is dependent on the temperature rating of the wire and the material. If it is NMD 90, 90 means 90 degrees. Please confirm if copper or aluminum. According to table 2 for up to 3 #6 wire in a cable you can supply up to 75A. If you prefer you can upsize your breaker to a 60A to supply more current. This is important because most breakers are only rated for 80% so really your 40A breaker is only 32A to the charger. So with a 60A breaker you get 48A to charger a 50% increase.
As for the wire routing there is rules on the number of bends in conduit for every junction box. All wiring must be mechanically protected. If it’s NMD 90 it must be in a wall assembly or in conduit. Depending on the charger some of them can be fed from the back or inside the wall. If possible route the wire in the wall or on other side of the wall and come directly into the charger. I wouldn’t recommend wrapping around with conduit.
What charger are you planning to use?
Source: Electrical engineer consultant
Loon610 OP t1_ir34d0y wrote
Thanks for the input. It’s a Grizzl-e charger. It has a max charge amperage of 40 amps, which would require a 50 amp breaker. The charger has dip switches which can be set to max amps of 16,24,32 or 40 amps. The vehicle is plug in hybrid so it only asks for an input amperage of about 14.2 amps, so I was going to set the dip switch at 24 amps just to be save, although I do believe the manual says to set them at you rated breaker which would be 40 amp breaker and 32 amp dip switch. I’m happy to keep it at 32 amps max charge because even if we got another ev r phev that could handle more amperage, from my understanding the higher amperages are not good for the batteries, and it being a home charger 32 amp would be more than enough to top off or add to what our daily use would be, we would have to be doing long road trips daily to have need for faster charging at home. The reason I want to install now, is there is government rebates to do so, we plan on staying in the home for decades to come and don’t see EVs becoming more common and why not take the rebate now, because 5 years they probably won’t offer it.
The wire will run from the panel up the wall, into the attic and down the wall on the other side of the garage. That wall is shared between garage and carport and the charger will be on the carport side. The issue with going straight into the charger is the design of the charge requires to sit on the wall not in it, and the input only comes in from the bottom. The panel was an upgraded one and added after the house was built, so it sits on the old siding not flush in the wall, funny enough some the NMD wire they installed is just stapled against the old wood siding in the garage (I believe it was a carport and someone enclosed it), so then would that NDM be to code. An electrician did do the work as far as I know, they didn’t some bigger renovations when the house service was upgraded to 200amp.
awtivy t1_ir35wc0 wrote
While you’re doing it all I’d recommend going to the 50A breaker especially if you’re getting a permit and inspected so you only have to do it once! You can always lower the charging rate with dip switch or most cars will let you lower charging rate too. Charging at 40A isn’t going to affect your batteries noticeably. However DC fast charging at 50KW will!
There is a rule that if NMD is above 1.5m I believe it doesn’t need to be mechanically protected.
awtivy t1_ir3i18k wrote
Another option would be to put a junction box on the exterior attic wall. This could serve as a junction point between the NMD90 and either some TECK90 (outdoor armoured cable) or flexible conduit or ridged conduit. Theoretically you can remove the sheath from the NMD90 up to the transition to conduit but I would just size the conduit so it fits with the sheath on. Then just get one 90 for conduit and one of the right angle watertight grommets.
https://www.homedepot.ca/product/southwire-1-inch-liquid-tight-non-metallic-simpush-90-degree-connector/1001386626 Assuming it’s a 1” knock-out.
Also looks like the they are ring terminals so you may need to get bigger rings for #6 wire from lordco or another electrical store.
Loon610 OP t1_ir3sqib wrote
Thanks for the idea, I think I will still come in from the bottom though to avoid the 180 turn with conduit or armoured cable to get in the charger, they say it can be mounted upside down inside but then it’s not guaranteed waterproof. Lordco eh, I see you’re a fellow BC’er haha.
So my plan is either keep the 40amp breaker or possibly upgrade to 50amp, NMD 90 6-3 wire to a junction box in garage wall just on the other side of charger carport location, strip jacket (not insulation)of wire, then from the junction box run wire through flexible non metallic conduit straight into charger through the wall into carport where charger is. What’s your thoughts? Any ideas? Also some have pointed out some jurisdictions require a disconnect switch wired in the circuit, I’m in the Okanagan so we just follow provincial code we don’t have city specific codes like Vancouver. I know disconnects are required for air conditioners here, do you know anything about them for EVS?
awtivy t1_ir3v85j wrote
As far as I know no disconnect required because an EV charger is not really a serviceable appliance. The point of a disconnect on AC unit is so when the AC guy comes to clean it he can easily turn it off and lock it out. For an EV charger it’s just passing power to your car.
The inspector will probably want the NMD inside to be in conduit for the section that is below 1.5m. I would use the watertight right angle connector I sent and just a drill a hole to put it right into the wall right into the back of a junction box inside garage. Then a chunk of conduit up to the 1.5m line and you can run the wire stapled to wall up high.
Loon610 OP t1_ir5qk7k wrote
If you don’t mind would you be able to look at this article for me and see if you see anything I’m missing. Another poster posted in relation to codes, but it seems they may not apply, he talked about ventilation being required but by the code that applied to indoor charging and carports by code are considered outdoors, this carport is also open on 3 sides so lots of ventilation.
From the article “Rule 86-304 requires that each installation of electric vehicle supply equipment rated at 60 A or more, or more than 150 volts-to-ground be provided with a separate disconnecting means
• on the supply side of the point of connection of the electric vehicle supply equipment • located within sight of and accessible to the electric vehicle supply equipment • capable of being locked in the open position”
I’m not exceeding 60amps or 150 volts to ground right? 240 volt is 120 to ground but each leg.
Another rule from the article, the other posted claimed I would need GFCI citing this rule, it only speaks of receptacles which I’m not installing, I’m surprised it seems to only call for GFCI on 120 volt circuit and does not mention it on 240 volt, but maybe that is indirectly mentioned in the second line where it mentions appropriate CSA configuration?
“Rule 86-306 requires that each receptacle for electric vehicle charging be
• a single receptacle of CSA configuration 5-20R supplied from a 125 V branch circuit rated not less than 20 A, protected by a Class A GFCI if installed outdoors within 2.5 meters of finished grade
• of the appropriate CSA configuration in accordance with Diagram 1 or 2 when supplied from a branch circuit rated at more than 125 V or more than 20 A
• labelled in a conspicuous, legible, and permanent manner, identifying it as an electric vehicle supply equipment receptacle”
Thanks again for the help, anything I’m missing here?
awtivy t1_ir8dur1 wrote
So this article was not written very well and neither was the new code rules…
Either way looks like the intent is to have gfci only on a receptacle intended to be used for EVs. Since you are hardwiring yours it’s not required.
Loon610 OP t1_ir8hvv9 wrote
Thanks a lot again for the help, very appreciated. I’m not in the industry so sometimes I worry I’m misunderstanding something or missing something.
awtivy t1_ir8dx0b wrote
Also you’re correct in not exceeding 60A or 150V
Andy802 t1_ir31n6m wrote
I would double check that you don’t need neutral. Some ev chargers work work without them, and/or a specific resistance between ground and neutral. Found this out the hard way when trying to charge our Kona from a generator last weekend…
Loon610 OP t1_ir3st3z wrote
Thanks, company stated no neutral needed. It’s a Grizzl-e charger.
Material_Community18 t1_ir3ciac wrote
(Not an electrician but an EV owner) EV tech is changing so fast you should not skimp. Keep the biggest wire possible, keep the neutral as far as possible. If you buy a Ford F-150 Lightning they will recommend the Ford Charge Station Pro: 80A (100A circuit). I thought my 10AWG wiring would be plenty when I had it installed 7 yrs ago…
timg528 t1_ir3fz45 wrote
Sounds like a solid plan. I'd double check that it can't take #6 wire. If it can't, go for it and if you ever need to, you can turn it into a 40 amp outlet.
fixITman1911 t1_ir3na8t wrote
I'm all for DIY stuff normally, but IMO any time you are looking at a project with higher than 12 gage wire, if you have to ask questions... you should really hire an electrician. This is the kind of stuff where "I think I did this right" gets people killed
Exciting_Ad9005 t1_ir3qd72 wrote
Also no need for a box. Makes no sense.
VonGeisler t1_ir47302 wrote
Does your EV not have an adapter for a regular 40A outlet? Cause for level 2 you generally don’t need an actual wall charger and it can be connected directly into the outlet. The advantages of the wall charger station are small.
frollard t1_ir4gkh5 wrote
I use the charge point (forget the model... High current version) and it doesn't like the 4 gauge wire that I ran. (got it on sale end of the roll)... Because I'm only running at 32a I don't mind(totally against code) trimming enough strands/cores to snugly fit the screw terminal on the evse. The correct move would be a junction with a suitable bus bar connector as you suggest... but I'm taking the charger/circuit with me when I move to somewhere I can put it on a 60-80 amp breaker safely... so not worried. The wire is super duper overkill in my case and not the weakest link.
ZanyDroid t1_ir4ppy7 wrote
There's a subreddit for these questions btw, r/evcharging. While a lot of the advice is more NEC focused, there is a lot of knowledge of EVSE that is generalizable to Canada. Also the EVSE advice is more focused than you've gotten in this post.
Looks like you've been well taken care of.
Few things that haven't been mentioned here in this thread, but are well-known over in that sub:
- there's been a rash of GrizzlE fires due to their crappy terminal block design and questionable quality control. Fortunately the metal case has done a good job of containing those fires, I guess
- it's critical to use a torque screwdriver on the terminals on your breaker and on the EVSE terminals, and torque to specifications. with the amount of current involved in charging your splices need to be rock solid. on the same note you want to make sure any wire nuts are twisted all the way/have the appropriate amount of insulation stripped off per manufacturer specs.
(Another discussion there is suspicion of how good of a job ETL and UL are actually doing on vetting EVSEs, which has led me to prefer EVSEs from more established manufacturers)
Loon610 OP t1_ir5mijg wrote
Thanks a lot for the info, I will have to post in there.
I’m surprised about the Grizzl-e catching fire. Every time I see someone doing a review they are raving about how over built and industrial grade it is. I guess these could just be paid reviews. Any EVSE you would recommend that could be hardwired? I liked the idea of Grizzl-e since it’s made in Canada which is rare to find as a Canadian, but I prefer the idea of zero fires more.
ZanyDroid t1_ir60a9s wrote
They were fairly well liked up until recently due to the nice exterior design. It's possible that this is forum people overreacting... but people do share photos of the after effect.
I think ClipperCreek, Autel, Chargepoint are ones I've heard of discussed over there & have popped out in my mind. Those are physically solid. Emporia is also getting into the space and stands out for having special features like peak management & integrating with the rest of their home energy management hardware, at an attractive price point.
Check the recent history on that sub for discussion threads.
Jim-N-Tonic t1_ir5s6hj wrote
Oooo, I like this project. Have a Crosstrek hybrid and would love to solar power my car!
[deleted] t1_ir2xipf wrote
[deleted]
jkoudys t1_ir35fai wrote
6 is bigger. It's a measurement based on the idea that you draw the wire more times the higher it goes, so it's thinner. He's saying that the hottub was relatively far away, so they used thicker wire for less resistance therefore less V drop. Now they're using the same run for an application where 6 awg is the appropriate size, as the charger will be much closer to the panel.
[deleted] t1_ir3qp1q wrote
[deleted]
Metsican t1_ir3bf5v wrote
[deleted] t1_ir3qhpe wrote
[deleted]
dclydeg86 t1_ir1p2g7 wrote
#6 will be fine, a #6 is rated for higher amps than a #8 so you wont have any issues, you can always upsize wire but never downsize wire. Just like the hot tub probably could have use the #8 but because of the voltage drop from the length of the wire #6 was used. #6 THHN is good for 75 amps as long as it doesnt pull 75 amps or more you will be fine using #6 and if you are still nervous about it call a local electrician.
Hunting_Gnomes t1_ir2qod0 wrote
I DONT KNOW WHAT WE'RE YELLING ABOUT!!!!
LOUD NOISES!!!!
BangkokPadang t1_ir2ccqu wrote
Wow, I never thought about using the formatting markup to make my post obnoxiously large to force everyone’s attention to it. This is brilliant!
Viper67857 t1_ir31cbd wrote
He probably doesn't know how to escape that first pound sign... That, or never bothered looking back at his comment after posting it.
BangkokPadang t1_ir3k2es wrote
#actually i bet you’re right
ztpurcell t1_ir322zd wrote
You apparently aren't brilliant enough to deduce that the # sign boldens text
BangkokPadang t1_ir2cdlo wrote
Wow, I never thought about using the formatting markup to make my post obnoxiously large to force everyone’s attention to it. This is brilliant!
ark_mod t1_ir1f3bz wrote
I'm not a contractor but I have done some electrical work.
In my experience this could be an issue. What happens if someone moves in after you, looks at the circuit wiring in your fuse box and assumed the 6 guage was wired to the outlet. They could try to draw too much power and start the wires on fire. Assuming your breaker is sized correctly this shouldn't be an issue.
Your concern on bending the wire is invalid in my opinion. Wires are meant to be bent - just not repeatedly. I would use the thicker guage wire the entire run. Have you considered mounting the charger to a different joist and running the wire at a 90 rather than a 180?
Loon610 OP t1_ir1hqqn wrote
I understand this concern, but there will be no “outlet”, it will run about 30’ from the main panel, to the junction box, and about 1-2 feet from there to the hardwired charger. I’m avoiding a receptacle because then my kids can’t mess with unplug or plug charger in, harder to steal and no need for a new 280 dollar gfci breaker which is need if it’s no hardwired, the charger has a gfci built in, but I understand if it’s receptacle who knows what will be plugged in.
jay_mald t1_ir2r3gu wrote
Actually, bending wires to a certain extent is against NEC standards.
Source NEC 300.34
“The conductor shall not be bent to a radius less than 8 times the overall diameter for nonshielded conductors or 12 times the overall diameter for shielded or lead-covered conductors during or after installation. For multiconductor or multiplexed single-conductor cables having individually shielded conductors, the minimum bending radius is 12 times the diameter of the individually shielded conductors or 7 times the overall diameter, whichever is greater.”
If you aren’t a professional electrician I don’t recommend giving advice that can potentially harm someone.
mr_sarve t1_ir2ptrf wrote
I'm always amazed that it is apparently legal to do stuff like this yourself in the US. In my country you would not only need an electrican to do it, but it would require a dedicated fuse and a surge protector
Loon610 OP t1_ir2w5xw wrote
I’m not in the USA, I’m Canadian. I don’t see why someone shouldn’t be able too, like I said I have to pull a permit, someone from the Provincial Technical Safety will come and inspect my work, before I can flip the breaker. If I hired someone there would be no inspection, electricians can pull their own permits and do not require inspections, and as a Red Seal Tradesperson myself, I can tell you just because someone is a Red Seal doesn’t mean they do the job right, maybe they were taught wrong, maybe they just make it work with the materials they have, maybe they are in a rush. One thing I can tell you is no one cares about your home more than you do, and if you hire every job out you will eventually have butchers show up to your house. I’m not an expert, but I do make sure to double check all my work, and if I’m unsure I ask and research, I’ve actually been to my local library to look up codes because they have building codes on hand free to use there. I couldn’t do this work if I lived in a apartment or duplex, only a detached home and I can only do it to a home I live in, not even a home I own and rent. The regulations are strict but good, someone should be free to work on their own home if they can have their work inspected, and if you think every certified person will do the job right, they won’t and if every homeowner will apply for a permit and do they work properly, they won’t. It’s best to try to learn as much as you can from roofing to auto repair, because you need to know when you’re getting taken for a ride, because it will happen.
[deleted] t1_ir1eiso wrote
[deleted]
Sparkykc124 t1_ir1px5z wrote
I am an electrician and this is not true, at all.
Randomperson1362 t1_ir1mt8r wrote
I'm not an electrician, so don't listen to me, but what is the harm in going with smaller wire?
Lets say you have 60 amp wire, then in a junction box you add connect 40 amp wire to lengthen the circuit. Assuming a 40 amp breaker* is that an issue?
Obviously using a 60 amp breaker is a very bad idea.
Princess_Moon_Butt t1_ir1ztv8 wrote
Exactly. If you use wire that's rated for less than the breaker's capacity, yes, that's bad.
This guy's talking about using a 40-amp breaker, with a mix of 60-amp wire and 40-amp wire. There's no concern there, because the most that will go through that 40-amp wire is 40 amps.
eerun165 t1_ir1vd96 wrote
Wire size can be increased in size to account for voltage drop.
Decreasing wire size from its corresponding breaker is a fire risk. The wire is not rated for the higher current and will heat up (think of the small wires in a toaster).
Viper67857 t1_ir324xm wrote
It's still a 40A circuit on a 40A breaker, it just has wire rated for 55A along most of the run. Using a couple feet of 8ga at the end will not hurt anything.
You already downsize the massive 200A cables coming into your service entrance with 15-20A wires going to most of your devices, then those devices may have some tiny 20+ga wires inside them. You use what you need for the individual load, you don't just carry on the larger cable for consistency.
TrumpsPissSoakedWig t1_ir2iaw7 wrote
Make another post claiming you figured out the most superior way to do it. Make sure it's a totally made up and incorrect method.
Then, an expert will write an entire detailed post explaining how to do it right, because people love to correct someone more than helping them.